Koi pond Water pressure

[Sjp98e]

Hello community I'm in the process of using an existing planter box constructed out of marble stone. The side walls, particularly the outside one on the patio side are the thickness of the stone plus the about 6" of dirt. My question is about the pressure of water on this wall. I have calculated this pond will be 500 gallons. Do I need to build any support for this wall. The original planter bos had 2 small trees and shrubs with no roots pushing on the said walls.

 

[Mmathis]

Hello and welcome!

Sorry, but I can only ask questions, not give advice, as I’m not experienced with this sort of build.

Where are the other sides going to be? It looks like you have the excavation up against a building. How deep will this be, and how much will be above vs below ground?

Also, please reconsider koi, as your title says. Goldfish will be better suited for a 500 gallon pond.

 

[j.w]

@Sjp98e

 

[poconojoe]

It looks like you plan to turn a planting area up against your house into a water feature.

From the looks of it, it seems the wall is most likely built out of some type of block, then the marble was applied.

It looks pretty strong from the pictures, but not actually being there, it's hard to tell.

I don't know what the pluses and minuses of being up against the house would though.

Overall, I think you will be ok.

I will agree with @Mmathis As to the size not being appropriate for koi.
500 gallons is way too small for even one koi.
Look into shubunkin. They are beautiful fish with long flowing fins and nice colors. They are in the goldfish family and stay relatively small, especially compared to koi.

 

[netvine]

Everyone thinks my shubunkins are koi, i would t have known either until recently.

 

[CometKeith]

Hello community I'm in the process of using an existing planter box constructed out of marble stone. The side walls, particularly the outside one on the patio side are the thickness of the stone plus the about 6" of dirt. My question is about the pressure of water on this wall. I have calculated this pond will be 500 gallons. Do I need to build any support for this wall. The original planter bos had 2 small trees and shrubs with no roots pushing on the said walls.

Hi and welcome! To determine the forces someone would need to know how deep the pond is going to be. I’m guessing it won’t be more than a foot or two. Personally I think you will be fine because most of the force is down and not sideways from a pond. I‘m guessing you are going to use a liner? You can always do a dry run.. actually “wet” run. Clean the inside out like you are doing, plop down a liner and fill it with water and see if any of the stone is cracking at the seams or moving. You can always make a reference point with a few sticks and string to see if the walls move closer to the string. My guess is if it’s okay for a week or so you are probably good to go. Also re fish: the concept is start with something easy so you have a high likelihood of success. Larger fish require a lot more work and more often than not people have bad experiences if they go with too high of a bioload. Then they are on the forum asking how to cure sick and dying fish and that is no fun at all! My recommendation is start with two small goldfish for the first month and then add a couple more after you know the pond has cycled and you are a little more experienced. Also a fun fact: the fewer fish you put in the pond the more babies you will get! Good luck!

 

[poconojoe]

Everyone thinks my shubunkins are koi, i would t have known either until recently.

Yep, I love them!
They come in various colors, including solid colors, some with specks and some are opaque. Their fins are gorgeous.